Respuesta :

Answer:

2.4 cm

Step-by-step explanation:

Formula

[tex]V = \pi r^{2} h[/tex]

Substitute Known Variables

[tex]138 = (3.14)(r^{2})(7.8)[/tex]

Multiply Known Variables

[tex]138 = (24.292)(r^{2} )[/tex]

Divide Volume By 24.292

[tex]\frac{138}{24.292} = r^{2}[/tex]

[tex]5\frac{4135}{6073} = r^{2}[/tex]

Find The Squared Root Of Both Numbers

[tex]\sqrt{5\frac{4135}{6073} } = \sqrt{r^{2} }[/tex]

[tex]2.38346021471... = r\\r = 2.38346021471...[/tex]

Round The Answer To The Nearest Tenth

2.4 cm